As an answer to the question of 'How do you automatically set the focus to a textbox when a web page loads?', Espo suggests using
<body onLoad="document.getElementById('<id>').focus();">
Ben Scheirman replies (without further explanation):
Any javascript book will tell you not to put handlers on the body element like that
Why would this be considered bad practice? In Espos answer, an 'override' problem is illustrated. Is this the only reason, or are there any other problems? Compatibility issues?